In the prior art, a washing machine is generally classified as a drum washing machine, a pulsator washing machine, and an agitator washing machine.
The pulsator washing machine agitates the water stream by means of a pulsator and then water stream moving randomly agitates laundry, so as to complete a washing process and a rinsing process of laundry.
The agitator washing machine drags laundry to move in water directly or indirectly by virtue of a force of water by means of an agitating upright pole, so as to complete washing of laundry.
In principle, the pulsator washing machine and the agitator washing machine are quite similar.
In development of the pulsator washing machine, a technical solution using a plurality of pulsators is disclosed in many documents, examples of which are as follows.
Disclosed is a washing machine having a plurality of pulsators in FR1131586. The plurality of pulsators may be horizontally or obliquely provided at a bottom of a washing tub, which may rotate in the same direction or in different directions.
Disclosed is a top loading type washing machine having a spherical washing basket in U.S. Pat. No. 5,829,277 A. The side agitators having the shape of a spherical segment are mounted on the washing basket, the two agitators rotate only in the same clockwise direction or the same counter-clockwise direction (as viewed from facing the agitators) due to the limitation on the transmission thereof.
Disclosed is a washing machine having a pulsator device in CN1170056. The pulsator device comprises: a driving pulsator mounted on a bottom of a drum and driven by a motor to rotate and a plurality of driven pulsators rotating around respective axes of support shafts fixed on a side wall of the drum under driving of the driving pulsator.
Disclosed is an agitator of a washing machine in CN1200416, the washing machine has a washing tub, and at least two oblique portions protrude inwardly on a bottom of the washing tub. A washing shaft on which extends upwardly from the bottom of the washing tub and is rotatable. A driving wheel is mounted on the washing shaft, and on a side face of which a frictional plane is formed. There are at least two frictional wheels which are rotatable and contact the frictional plane of the driving wheel. There are at least two driven wheels, frictional planes on a side of which contacts the frictional wheels respectively, wherein the driven wheel is rotatably mounted on one plane of the oblique portions. At least two agitating blades are mounted on the other plane of the oblique portions.
Disclosed is a transmission apparatus of a speed reducing clutch of a washing machine in CN2778852, which comprises an upper case cover, a lower case cover above which the upper box cover is fixed, an output shaft, a pulsator shaft, a dewatering shaft further connected with the lower case cover, a driving gear, a driven gear, and a speed reducer transmission system with which the pulsator shaft and the dewatering shaft are connected. The driving gear and the driven gear are sheathed respectively at a periphery of the pulsator shaft and at a periphery of the output shaft, and the driving gear and the driven gear are engaged. An upper end and a lower end of the output shaft are mounted respectively to the upper box cover and the lower case cover.
Fundamental objects of the above technical solutions using a plurality of pulsators in the prior art are to realize complex a water stream so as to reduce wrapping of washed laundry and improve the cleaning rate of the washed laundry. Their objects and the technical solutions are not intended to realize a rolling effect in an upright tub type washing machine similar to that in the drum washing machine.
The drum washing machine lifts laundry by means of a plurality of ribs fixed to an inner wall of an inner tub so as to repeatedly lift laundry and make laundry fall in the inner tub so as to complete a washing process and a rinsing process.
It was considered in the prior art that the agitator washing machine and the pulsator washing machine have higher cleaning rates, shorter washing times, and are relatively easy to control balance during spin-drying at a high speed. However, such kinds of washing machines have higher wear and tear, higher water consumption amount and relatively serious wrapping of laundry.
The drum washing machine has a lower cleaning rate, lower wear and tear, lower water consumption amount, and less serious wrapping of laundry. However, it requires longer washing time and is relatively more difficult to control balance during spin-drying at a high speed.
The people skilled in the art have researched for decades and have not attained an effective means until now on how to combine advantages of and simultaneously remove deficiencies of the above different washing machines.
US MAYTAG Company proposes a beneficial concept which is specifically as follows. U.S. Pat. No. 6,220,063 B1 discloses a washing machine, two agitators in this document rotate respectively in a clockwise direction and an counter-clockwise direction, and when they are provided as shown in the drawings, they form lifting and falling effects similar to those in the drum washing machine.
The technical solutions disclosed in this document certainly present a concept that the rolling action is realized by pulsators in an upright tub washing machine.
However, this solution also has many deficiencies. For example, it requires the pulsator to be very large and to have a close match at an engaging point between the pulsator and the inner tub so as to prevent laundry from being clamped. Furthermore, regardless of a distance between lower ends of the two pulsators, it is quite difficult for a small amount of laundry to form a lifting and a falling process. Moreover, for a practical product of this solution, laundry often forms a “Rugby ball” shape during the washing process. So that laundry inside and laundry outside can not be exchanged and thus washing uniformity is lowered.
This document is incorporated into the present invention as a main document in the background field. And the present invention omits some description on the prior art. Corresponding contents disclosed in this document may be directly referenced and will not be described in details in the present invention.
CN1721610 discloses a suspension-type dual-pulsator washing machine and declares that it has the following features: a rolling effect as the drum washing without wrapping, has lower wear and tear, simultaneously has advantages of a high cleaning rate and saving water consumption as the pulsator washing, and has washing processes which may be performed as long as the highest water level reaches to ¼˜½ height of the pulsator. However, because it does not disclose a size of the pulsator, an angle providing the pulsators and an inner diameter of a tub, the initial water amount is not a determined value.
Maytag possesses the 2 above said patents which are similar to that disclosed in CN200520133107.X and CN2005100801 34.X. It has quite a lower probability to exchange and arbitrary exchange laundry inside and laundry outside in a laundry ball, thereby causing differences in washing uniformity of laundry.
A previous patent application, i.e. CN101191285A (2008 Jun. 4), of the applicant of the present invention discloses a vertical multi-pulsator washing machine. That has are three or four pulsators pivotally correspondingly provided at 120 degrees or 90 degrees around an inner wall of an inner tub. Washing processes may be performed as long as incoming water amount reaches to a ⅓ height of the pulsators. All the pulsators may rotate simultaneously clockwise or counter-clockwise to wash laundry. This application is an improvement on the pulsator washing machine with a principle in the prior art, since the pulsators rotate “simultaneously clockwise or counter-clockwise”. It can not attain a rolling mode having two rolling faces as described in the present invention. Moreover, because diameters of the pulsators, parameters of an inner tub, and the like are not determined, the rated incoming water amount is not a determined value.
A previous patent application, CN101191286 A (2008 Jun. 4, JULONG company), of the present invention discloses a multi-pulsator washing machine. Which have are three or four pulsators. During washing cycles, the three or four pulsators rotate in the same direction or in different directions in an inner tub. According to the two embodiments disclosed, similarly, it is not possible to attain the effect of the present invention, and it rolls, agitates, impacts, compresses, tapes, or rubes laundry by means of water stream.
A previous patent application, CN201176525A, of the applicant of the present invention, discloses a full-automatic multi-pulsator washing machine which mainly is an improvement on a driving mode of the prior art.
All the prior arts and practical products thereof, in addition to the complex structure of the pulsator, high cost, and large noise, the most serious deficiency lies in that laundry repeatedly rolls at most on one assumed plane when a mode using two pulsators are obliquely provided. Similar to the drum washing machine in the prior art, it can not realize to make laundry roll in more than one direction. Also, when an amount of laundry is small, it is quite difficult to realize rolling, and it is easy to form a “Rugby shape” when laundry rolls in one direction.